What is 5G RedCap

The gap it fills

Original 5G was designed for three extremes: enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC) and massive IoT, which in practice is still served by NB-IoT and LTE-M. That left a gap: devices that need more than LTE-M but not a smartphone-class 5G modem. 3GPP started the work in 2019 and closed the specification in Release 17 (2022). Ericsson's overview of the design estimates that an FR1 RedCap device carries roughly 65% less complexity than the reference 5G device.

What it cuts from full 5G

The cost saving comes from removing capability an IoT device does not use. Per the specification (TS 38.300) and the Release 17 work item:

• ·Maximum bandwidth of 20 MHz in FR1 (bands below 7 GHz) and 100 MHz in FR2 (mmWave), versus 100 MHz or more on a 5G phone.
• ·1 or 2 receive antennas, with 1 or 2 downlink MIMO layers.
• ·64QAM is mandatory; 256QAM is optional.
• ·Optional half-duplex operation in FDD bands: the modem does not transmit and receive at the same time, so it can drop the duplexer.
• ·No carrier aggregation and no dual connectivity.

Data rates: more than you might think, less than the brochures say

For a RedCap device with the minimum configuration (1 antenna, 64QAM, 20 MHz), Ericsson puts physical-layer peaks at about 85 Mbps down and 90 Mbps up in FDD bands, and about 60 Mbps down and 20 Mbps up in TDD (30 kHz subcarrier spacing, 3:1 pattern). The TDD case is the one that matters in the 3.5 GHz band most European 5G networks use. Two antennas double the downlink and 256QAM adds about 33%. The 150 or 220 Mbps figures in product sheets belong to modules with those options, not to the minimum. For reference, 3GPP's RedCap requirements put an economy surveillance camera at 2-4 Mbps uplink and a high-end one at 7.5-25 Mbps.

Battery: long eDRX and fewer measurements

Release 17 gives RedCap two power-saving tools: idle-mode eDRX with cycles of up to 10,485.76 seconds (about 2.9 hours) in RRC_IDLE and up to 10.24 seconds in RRC_INACTIVE, and relaxed neighbor-cell measurements for devices that do not move. That does not make RedCap an LPWA technology: a battery sensor sending a few bytes a day is still better served by NB-IoT or LTE-M with PSM.

eRedCap: Release 18 goes one step lower

Release 18 (closed in 2024) defines eRedCap, or enhanced RedCap. It sets a mandatory 10 Mbps peak in both directions and optionally lets the device process data in only 5 MHz of baseband while keeping 20 MHz of RF. In practice it is the 5G counterpart of LTE Cat-1: it runs on the same network as RedCap and targets cheaper modules. e& tested eRedCap on its commercial network in the UAE at 10 Mbps over 5 MHz, and GSA expects commercial eRedCap chipsets and devices in early 2027.

The requirement people forget: 5G Standalone

RedCap only attaches to 5G Standalone networks with a 5G core (5GC). It does not work on 5G NSA, the 5G that rides on the 4G core and is still most of the world's deployment. According to GSA, in October 2026 there were 98 operators with commercial 5G SA against more than 390 with 5G, and, as of September, 17 operators had launched RedCap with 43 investing in it across 28 countries. In Europe, Deutsche Telekom was first in September 2025, followed by O2 Telefónica in Germany and MasOrange in Spain, which includes RedCap in the 5G Advanced layer it is rolling out on its 5G SA network.

What it means for your SIM and for roaming

The module is not enough: the line has to be provisioned in the operator's 5G core. A SIM that only gets 4G or 5G NSA on that network will not attach as RedCap even if the modem supports it. In Spain, iot.cards SIMs register on 5G SA on Orange's network, which is the Spanish network with RedCap live. Roaming is the other limit: according to Kaleido Intelligence, 5G roaming still relies almost entirely on NSA and SA roaming is only starting in 2026. A RedCap device that travels between countries needs LTE fallback in the module, or it will lose service wherever it finds no 5G SA.